Entries Tagged "point of sale"

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Interesting Attack on the EMV Smartcard Payment Standard

It’s complicated, but it’s basically a man-in-the-middle attack that involves two smartphones. The first phone reads the actual smartcard, and then forwards the required information to a second phone. That second phone actually conducts the transaction on the POS terminal. That second phone is able to convince the POS terminal to conduct the transaction without requiring the normally required PIN.

From a news article:

The researchers were able to demonstrate that it is possible to exploit the vulnerability in practice, although it is a fairly complex process. They first developed an Android app and installed it on two NFC-enabled mobile phones. This allowed the two devices to read data from the credit card chip and exchange information with payment terminals. Incidentally, the researchers did not have to bypass any special security features in the Android operating system to install the app.

To obtain unauthorized funds from a third-party credit card, the first mobile phone is used to scan the necessary data from the credit card and transfer it to the second phone. The second phone is then used to simultaneously debit the amount at the checkout, as many cardholders do nowadays. As the app declares that the customer is the authorized user of the credit card, the vendor does not realize that the transaction is fraudulent. The crucial factor is that the app outsmarts the card’s security system. Although the amount is over the limit and requires PIN verification, no code is requested.

The paper: “The EMV Standard: Break, Fix, Verify.”

Abstract: EMV is the international protocol standard for smartcard payment and is used in over 9 billion cards worldwide. Despite the standard’s advertised security, various issues have been previously uncovered, deriving from logical flaws that are hard to spot in EMV’s lengthy and complex specification, running over 2,000 pages.

We formalize a comprehensive symbolic model of EMV in Tamarin, a state-of-the-art protocol verifier. Our model is the first that supports a fine-grained analysis of all relevant security guarantees that EMV is intended to offer. We use our model to automatically identify flaws that lead to two critical attacks: one that defrauds the cardholder and another that defrauds the merchant. First, criminals can use a victim’s Visa contact-less card for high-value purchases, without knowledge of the card’s PIN. We built a proof-of-concept Android application and successfully demonstrated this attack on real-world payment terminals. Second, criminals can trick the terminal into accepting an unauthentic offline transaction, which the issuing bank should later decline, after the criminal has walked away with the goods. This attack is possible for implementations following the standard, although we did not test it on actual terminals for ethical reasons. Finally, we propose and verify improvements to the standard that prevent these attacks, as well as any other attacks that violate the considered security properties.The proposed improvements can be easily implemented in the terminals and do not affect the cards in circulation.

Posted on September 14, 2020 at 6:21 AMView Comments

Chip Cards Fail to Reduce Credit Card Fraud in the US

A new study finds that credit card fraud has not declined since the introduction of chip cards in the US. The majority of stolen card information comes from hacked point-of-sale terminals.

The reasons seem to be twofold. One, the US uses chip-and-signature instead of chip-and-PIN, obviating the most critical security benefit of the chip. And two, US merchants still accept magnetic stripe cards, meaning that thieves can steal credentials from a chip card and create a working cloned mag stripe card.

Boing Boing post.

Posted on November 15, 2018 at 6:24 AMView Comments

iPhone Payment Security

Apple is including some sort of automatic credit card payment system with the iPhone 6. It’s using some security feature of the phone and system to negotiate a cheaper transaction fee.

Basically, there are two kinds of credit card transactions: card-present, and card-not-present. The former is cheaper because there’s less risk of fraud. The article says that Apple has negotiated the card-present rate for its iPhone payment system, even though the card is not present. Presumably, this is because of some other security features that reduce the risk of fraud.

Not a lot of detail here, but interesting nonetheless.

Posted on September 8, 2014 at 7:21 AMView Comments

Attack Against Point-of-Sale Terminal

Clever attack:

When you pay a restaurant bill at your table using a point-of-sale machine, are you sure it’s legit? In the past three months, Toronto and Peel police have discovered many that aren’t.

In what is the latest financial fraud, crooks are using distraction techniques to replace merchants’ machines with their own, police say. At the end of the day, they create another distraction to pull the switch again.

Using information inputted by customers, including PIN data, the criminals are reproducing credit cards at an alarming rate.

Presumably these hacked point-of-sale terminals look and function normally, and additionally save a copy of the credit card information.

Note that this attack works despite any customer-focused security, like chip-and-pin systems.

Posted on June 19, 2012 at 1:02 PMView Comments

More European Chip and Pin Insecurity

Optimised to Fail: Card Readers for Online Banking,” by Saar Drimer, Steven J. Murdoch, and Ross Anderson.

Abstract

The Chip Authentication Programme (CAP) has been introduced by banks in Europe to deal with the soaring losses due to online banking fraud. A handheld reader is used together with the customer’s debit card to generate one-time codes for both login and transaction authentication. The CAP protocol is not public, and was rolled out without any public scrutiny. We reverse engineered the UK variant of card readers and smart cards and here provide the first public description of the protocol. We found numerous weaknesses that are due to design errors such as reusing authentication tokens, overloading data semantics, and failing to ensure freshness of responses. The overall strategic error was excessive optimisation. There are also policy implications. The move from signature to PIN for authorising point-of-sale transactions shifted liability from banks to customers; CAP introduces the same problem for online banking. It may also expose customers to physical harm.

EDITED TO ADD (3/12): More info.

Posted on March 5, 2009 at 12:45 PMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.